Electric Field Calculation and Structure Parameter Analysis of Dumbbell Type Tri-post Insulator

摘要

Gas insulated metal enclosed line (GIL) has a lot of advantages on electromagnetic environment, current capacity and stability. As for the unique characteristic of GIL, mature products of GIL are more preferable to the high voltage transmission field in some situations. With the voltage level increasing, the insulation designs have a high level of challenges and difficulties. The world's first 1100 kV GIL has been building in China from Suzhou to Nantong. In order to ensure the safety and stability of this transmission projects, improve the reliability of the electrical insulted system, it is necessary to optimize the structure of GIL. In this paper, based on the structure of the GIL, the full three-dimensional (3D) finite-element method (FEM) model was built for numerical simulation. Then, the electric field distribution was calculated by COMSOL Multiphysis and the key parameters including radius of the post, width and inclination angle of dumbbell structure and some other parameters were changed to tell the effect law of dumbbell type structure to the electric field distribution. The results indicated that the change of different parameters will have different effects on the electric field distribution. The research conclusions can provide reference for insulation structure design and the GIL tri-post insulator production.